Season 12 was kind of a game changer for “CSI: Crime Scene Investigation” with the introduction of several new characters and the departure of a long-time favorite.

Ted Danson joined the cast as D.B. Russell, replacing Lawrence Fishburne’s Dr. Ray Langston, but actually coming in more as an equal to Gil Grissom (William Petersen), as he oversees the night crew. Elizabeth Harnois joined the cast as Morgan Brody, who originally worked with the CSI team on a case in Los Angeles before making the move to Las Vegas — where her father just happens to me on the police force; and finally, Elisabeth Shue became a member of the crime lab, playing blood spatter expert Julie Finlay, who has some kind of past with Russell.

The season also marked the departure of Catherine Willows (Marg Helgenberger). Both the character and the actress opted out of the show for new challenges. Catherine to move to the FBI, Helgenberger it remains to be seen what she will do next.

Despite the juggling of so many new faces, the cases remained the same: challenging the CSIs to follow the evidence to track down the bad guys.

With all the changes, we checked in with Executive Producers Carol Mendelsohn and Don McGill to get their take on the highlights and lowlights of the season before the “CSI” season finale airs Wednesday, May 9 at 10 p.m. ET/PT on CBS.

Take us inside your approach to the finale, and what you wanted to accomplish.
At the beginning of the season, as we were developing the character of D.B. Russell — family man, life in balance — we started to think about his arc for the season. It occurred to us that the greatest threat to Russell would be a threat to his family. In the premiere, we introduced Russell’s wife as a mystery woman on the phone. And fans have been asking if they would ever meet her. The plan all along was to meet her in the finale. We also meet their daughter and granddaughter. We go home with Russell, and it is at that perfect blissful home that we show the ultimate invasion. This will set up the season 13 premiere, where the team and Russell are challenged. We will definitely see a different side to Russell. His family is off limits and he will do whatever it takes to see his family made whole again.

Preview the Intense “CSI” Finale:

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Did anything disappoint you about this season? Anything you wish you could have done, but didn’t have the time, forethought or resources?
It was both a challenge and a struggle to introduce three new characters to the “CSI” family — Ted Danson, Elizabeth Harnois and Elisabeth Shue — and to say goodbye to a beloved star of the show — Marg Helgenberger. Arcing the arrivals and departure of cast members, it was hard to settle into a rhythm. It made the season feel more like a series of events than a cohesive exploration of the team and their cases. We’re looking forward to Season 13, the return of the cast and an opportunity to plan episodes that explore team dynamics and individual characters in a dynamic way.

What should fans look forward to next season? And if you haven’t gotten that far yet…what would your dream season be?
We start with our “Cape Fear”-style premiere, putting Russell and the team on the line. A villain from the past, former Under Sheriff Jeff McKeen (Conor O’Farrell), who took the life of CSI Warrick Brown (Gary Dourdan), is now out to get all of our CSIs. Also in the works is a mass killing at a favorite haunt of the lab rats. A trip back in time to old Vegas and the “Rat Pack.” And, on a personal front, the fans’ questions about the state of affairs between Grissom and Sara (Jorja Fox) will be answered.

What were the high points of the season?
One of our high points was also one of our saddest goodbyes in the history of the show — a dramatic three-part arc sending CSI Catherine Willows off to work with the FBI. One of the other high points was to see the team coalesce and become a family again around CSI Russell. The introduction of Elisabeth Shue as a blood spatter expert in the mold of Russell. The initial conflict between Russell and Brass. And, the warming of the once estranged [relationship between] CSI Morgan Brody and [her father] Under Sheriff Conrad Ecklie (Marc Vann), which ended up involving Hodges (Wallace Langham) and his mother played by Jaclyn Smith, in the most unlikely of double dates.

Do you have a favorite episode, line, or scene from this season? If so, what?
There were so many great scenes:
Russell and Brass (Paul Guilfoyle) walking into a tentacle porn strip joint.
Catherine and Russell in a mob museum.
Greg Sanders (Eric Szmanda) learning about his Norwegian roots from a genealogist played by Pamela Reed.
Meeting Dr. Robbins’ (Robert David Hall) wife and learning about his past infidelity in a scene between Doc and Catherine.
Nick (George Eads) and Greg having to process a crime scene at Doc Robbins’ house.
Sara going mano a mano with a serial killer and bonding with Russell over painful chapters in their past.
And maybe our favorite, seeing the team literally be a team… on the field in a softball game… where Henry (Jon Wellner) drives in the winning run.

Don’t miss the “CSI: Crime Scene Investigation” season finale on Wednesday, May 9 at 10/9c on CBS.